There are a few things I would find helpful:
1) If scripts in local_top could change the notion of ROOT.
I have a script that probes the system to find where the DFS CD is,
and then mounts it, since there is no ability to specify a custom
ROOT. Fortunately this works since the local script doesn't do
error-checking.
2) If scripts in local_top could override the fstype guess.
The fstype reports unknown for ISO9660 filesystems. Ideally it would
suport them, but even though it doesn't, it would be fine with me if
I could override the detected value.